Sen. Claire McCaskill has become the first lawmaker on Capitol Hill to publicly endorse Hillary Clinton for president in 2016. "It is important we start early," said McCaskill, a Missouri Democrat, in a statement posted at ReadyforHillary.com. "As I look at 2016 and think about who is best to lead this country forward, I’m proud to announce that I am Ready for Hillary."

McCaskill's support has come so early that she beat Clinton herself to the punch — the former secretary of State has yet to declare her intention to run. Indeed, even if Clinton jumps in the race, McCaskill's announcement will be a distant memory by the time the campaign actually begins.

So what is the point in making a public endorsement so early?

Some observers are taking McCaskill's move at face value, suggesting she simply wants to give Clinton an early boost in what is certain to be a bruising election. Taylor Marsh says at her blog that Ready for Hillary is urging supporters to come out for Hillary's candidacy now to help her build momentum. "Considering the U.S. has never had a female president," Marsh says, "with Republicans bent on destroying Clinton’s credibility years before she even makes the decision to run, which we saw through the Benghazi fiction furor on Fox News channel, no one should think 2016 will be a walk into the Oval Office."

Still, it's easy to see that McCaskill stands to benefit from getting the Clinton bandwagon started. Chris Cillizza notes at The Washington Post that "McCaskill was one of the leading — and most effective — spokespeople for then Illinois Sen. Barack Obama in 2008. That was a good thing for McCaskill then, but less so now, particularly because of her history with the Clintons."

Remember that in the fall of 2006, McCaskill went on Meet the Press and said this about Bill Clinton: "I think he's been a great leader but I don't want my daughter near him." Oomph. By endorsing Clinton so early, McCaskill is saying "I wasn't with you then but I am, big time, now." She's trying to heal the wound created by her endorsement and advocacy of the man who beat Clinton five years ago. [Washington Post]

Furthermore, McCaskill is perpetually considered one of the Senate's most vulnerable Democrats, given her state's increasingly red hue. That, says Geoffrey Norman at The Weekly Standard, suggests that McCaskill might be trying to ensure a soft landing if she loses her seat in 2018. "This development," Norman says, "may have as much to do with the senator's career plans as anything else. Secretary of labor, maybe?"

Or maybe McCaskill is hoping that Hillary Clinton will come to Missouri to help her in the next campaign, suggests Allahpundit at Hot Air. One thing seems clear, though, Allahpundit says: "The fact that she's willing to shank Joe Biden and other would-be Democratic contenders this early in the game tells you either (a) that she feels, probably rightly, that she has far more to fear from the Clintons than from any of their competitors or (b) that Beltway Democrats think Hillary's basically a lock to run and win the nomination."